The sight, smells, sounds and textures convey the science lesson more effectively than a textbook, said Tara Fuad, education director for the San Elijo Lagoon Conservancy.

“It encourages them to make their own discoveries and use their own senses,” she said. “Being able to see a snowy egret or a great blue heron, these majestic birds, gives them a sense of connection to the natural resource.”

Often overlooked by millions of drivers who cross them on commutes, lagoons have historically been derided as swamps. For example, the North County lagoon Agua Hedionda means “stinky water” in Spanish.

Those pungent tidal flats and salt marshes, however, are factories of life.

Teeming with fish and waterfowl, they’re some of the most biologically productive places on Earth. Prolific at capturing carbon and purifying water, they act as natural climate control systems and wastewater plants. Not to mention the aerial acrobatics of an osprey dive-bombing a fish.

But coastal highways and rail lines that transect the lagoons block tidal flows and disrupt their natural plumbing. California has lost about 90 percent of its historic wetlands, scientists say, so there are high stakes for preserving the remaining ones.

For years, individual lagoon conservancies have painstakingly restored hydrology and habitat and showcased the wetlands through nature walks and school visits. Now they’re coordinating plans for conservation and education.

Last month 120 lagoon managers, scientists, educators and public wildlife officials met at Del Mar Fairgrounds to compare notes. Discussion questions ranged from technical aspects of restoration to enlisting the public in protection.

Delaina Rojas-Jones, a fourth-grader from Skyline Elementary School in Solana Beach, discovers cottonwood tree leaves during an educational hike at San Elijo Lagoon. / photo by Bill Wechter * U-T San Diego

Delaina Rojas-Jones, a fourth-grader from Skyline Elementary School in Solana Beach, discovers cottonwood tree leaves during an educational hike at San Elijo Lagoon. / photo by Bill Wechter * U-T San Diego

“As we built this lagoon, you’ve got all the birds coming, and all the fish coming, but how do you get the people coming?” asked Kelly Sarber, a spokeswoman for the recently reconstructed San Dieguito Lagoon.

Each lagoon comprises a self-contained watershed, fed by local creeks. But they share common physical features and challenges.

A key problem is the closure of outlets at certain times of year. A strictly natural lagoon would see its opening meander across the beach as competing surf and freshwater flows rearrange its contours.

With transportation corridors blocking circulation, those openings seal up. That lowers the salinity and can spell trouble for saltwater plants and wildlife habitat. It can even trigger mosquito infestations.

Pollution, invasive plants and sediment buildup are other common problems.

To restore function, several lagoons have undergone multi-million dollar makeovers.

In the mid-1990s, the Port of Los Angeles funded a $50 million restoration project at Batiquitos Lagoon as mitigation for a port project, said Fred Sandquist, president of the Batiquitos Lagoon Foundation.

Scientists are converting scrubland at the South San Diego Bay National Wildlife Refuge Complex into an estuary, partially to compensate for the Poseidon desalination plant in Carlsbad.

San Dieguito Lagoon was carved from 150 acres of airfield and farmland in 2007, with $90 million mitigation funds for the now defunct San Onofre Nuclear Generating Station. The first year after construction, surveys found 12 million baby fish in the lagoon. The number of bird species last year was tallied at 217 — up from 59 before construction.

“We’re never going to get the ecology back to what it used to be in the early 1800s, because that would involve removing infrastructure and relocating hundreds of thousands of people,” said Mike Hastings, executive director of Los Penasquitos Lagoon Foundation.

That’s led to a “state of turmoil in the naturalist community,” said Jeff Crooks, research coordinator for the Tijuana River National Estuarine Research Reserve Some favor strict historical standards for lagoon restoration, while others say it’s okay to create entirely new wetlands.

“I tend to be of the camp that if we need to create something that didn’t necessarily exist in that place, but we can make it work, I’m okay with that,” Crooks said.

That may be important in years to come, he said. Wetlands can blunt storm surges and provide a “living, dynamic, natural response to sea level rise.” And they sop up more carbon than rainforests or prairies, he said.

“There’s basically no system better than our local estuaries at taking carbon and locking it away,” Crooks said.

They’re also what Gibson called a “smorgasbord” for the Pacific Flyway, with a tempting menu of insects, fish and crustaceans.

“It’s any bird’s Jack in the Box,” he said.

While your average egret recognizes the value of lagoons, Gibson and colleagues want to make sure that San Diego school kids do, too.

“One of the most important jobs we have is taking that scientific knowledge and making it into activities that a third and fourth grader can understand,” he said. “So you’ve to make it fun. You’ve got to make it cool.”

At San Elijo Lagoon last week, the Skyline students extracted iron from soil with magnets, spied a woodrat’s nest and scanned the scene with magnifying glasses.

The conservancy tries to build awareness upstream in the watershed along Escondido Creek, which feeds the San Elijo Lagoon. Students from several Escondido Schools visit the lagoon in third, fourth and fifth grade, Fuad said, building on their knowledge of waterways and wetlands. Some go back their schoolyards and start picking up trash near storm drains, she said.

At San Dieguito Lagoon, high school and college students do water testing or plant native vegetation through citizen science programs, Sarber said. It’s an open invitation to the next generation of marine scientists.

“Kids don’t realize that scientists are daily outside working in the water, working on animals, and that’s a well-paid career,” she said.

Once students are hooked on lagoons, their families take notice, Gibson said.

“There are a lot of reasons why wetlands are important,” Gibson said. “To each individual the reasons are their own. Because it offers respite, where they find peace. Because of it’s biological value supporting the Pacific Flyway. Because it filters water before it enters the ocean where we recreate. Each reason stands up on its own, but we need to be teaching the bigger picture about why it’s important.”